KR20250002484A - Light-emitting devices comprising quantum dot color conversion material and method for manufacturing the same - Google Patents

Abstract

A method of forming a light-emitting device comprises the steps of providing a free-standing support containing a matrix material including first and second vias, depositing a first photocurable quantum dot ink comprising first quantum dots suspended in a first photocurable polymer into the first vias, illuminating the first photocurable quantum dot ink with ultraviolet radiation or blue light from first LEDs of an array of LEDs to crosslink the first photocurable polymer material in the first vias, depositing a second photocurable quantum dot ink comprising second quantum dots suspended in a second photocurable polymer material into the second vias, illuminating the second photocurable quantum dot ink with ultraviolet radiation or blue light from second LEDs of the array of LEDs to crosslink the second photocurable polymer material in the second vias, and attaching the free-standing support to the array of LEDs after the illuminating steps.

Description

Light-emitting devices comprising quantum dot color conversion material and method for manufacturing the same

Related Applications

This application claims the benefit of priority from U.S. Provisional Patent Application No. 63/330,407, filed April 13, 2022, the entire contents of which are incorporated herein by reference.

Technical field

The present disclosure relates to light emitting devices, and more particularly, to light emitting diodes optically coupled with a color conversion material and methods of manufacturing the same.

Light-emitting diodes (LEDs) are used in electronic displays, such as backlights in liquid crystal displays in laptops and televisions, and in augmented reality (AR) displays. Such AR displays are high-resolution and small-sized displays that project at very high ppi (2000-8000) using micro-LEDs with widths of less than 10 microns, such as 1-2 microns.

An embodiment of a method of forming a light-emitting device comprises the steps of: providing a free standing support comprising a matrix material containing first and second vias; depositing a first photocurable quantum dot ink comprising a first plurality of quantum dots suspended in a first photocurable polymer material into the first vias in the matrix material; illuminating the first photocurable quantum dot ink with ultraviolet radiation or blue light from first light-emitting diodes of an array of light-emitting diodes to crosslink the first photocurable polymer material in the first vias; depositing a second photocurable quantum dot ink comprising a second plurality of quantum dots suspended in a second photocurable polymer material into the second vias in the matrix material, wherein the second plurality of quantum dots are configured to emit light at a different peak wavelength than the first plurality of quantum dots; and emitting the second photocurable quantum dot ink to crosslink the second photocurable polymer material in the second vias. The method further comprises illuminating the second photocurable quantum dot ink with ultraviolet radiation or blue light from second light-emitting diodes of the array of diodes, and attaching the free-standing support to the array of light-emitting diodes after the steps of illuminating the first and second photocurable quantum dot inks.

Another embodiment of a method of forming a light emitting device comprises the steps of: providing a plurality of light emitting diodes on a substrate such that the plurality of light emitting diodes are configured to emit incident photons of blue light or ultraviolet radiation; providing a color conversion device comprising a color conversion material formed in a plurality of vias in a matrix material; positioning the color conversion device relative to the plurality of light emitting diodes such that each of the plurality of vias is positioned over a corresponding light emitting diode of the plurality of light emitting diodes, wherein the color conversion material in each of the plurality of vias is configured to absorb incident photons from the corresponding light emitting diode of the plurality of light emitting diodes and generate converted photons having a peak wavelength longer than a peak wavelength of the incident photons; and adjusting the position of the color conversion device relative to the plurality of light emitting diodes to maximize the intensity of the converted photons having the longer peak wavelength.

A light emitting device of one embodiment comprises a color conversion device comprising a substrate, a plurality of light emitting diodes positioned on the substrate and configured to emit incident blue or ultraviolet radiation photons, and a color conversion material positioned in a plurality of vias in a matrix material. Each of the plurality of vias is positioned over a corresponding light emitting diode of the plurality of light emitting diodes such that the color conversion material in each of the plurality of vias is configured to absorb incident photons from a corresponding light emitting diode of the plurality of light emitting diodes and generate converted photons having a peak wavelength longer than a peak wavelength of the incident photons, and the color conversion device is a self-supporting structure attached over the plurality of light emitting diodes.

FIG. 1 is a vertical cross-sectional view of an intermediate structure that may be used in forming a light-emitting device according to various embodiments.
FIG. 2 is a vertical cross-sectional view of a light emitting device according to various embodiments.
FIG. 3 is a vertical cross-sectional view of an intermediate structure that may be used in forming a color conversion device according to various embodiments.
FIG. 4 is a vertical cross-sectional view of an additional intermediate structure that may be used in forming a color conversion device according to the first embodiment.
FIG. 5 is a vertical cross-sectional view of an additional intermediate structure that may be used in forming a color conversion device according to the first embodiment.
FIG. 6 is a vertical cross-sectional view of an additional intermediate structure that may be used in forming a color conversion device according to the first embodiment.
FIG. 7 is a vertical cross-sectional view of an additional intermediate structure that may be used in forming a color conversion device according to the first embodiment.
FIG. 8 is a vertical cross-sectional view of an additional intermediate structure that may be used in forming a color conversion device according to the first embodiment.
FIG. 9 is a vertical cross-sectional view of an additional intermediate structure that may be used in forming a color conversion device according to the first embodiment.
FIG. 10 is a vertical cross-sectional view of a color conversion device according to various embodiments.
FIG. 11 is a vertical cross-sectional view of an additional intermediate structure that may be used in forming a color conversion device according to a second embodiment.
FIG. 12 is a vertical cross-sectional view of an additional intermediate structure that may be used in forming a color conversion device according to a second embodiment.
FIG. 13 is a vertical cross-sectional view of an additional intermediate structure that may be used in forming a color conversion device according to a second embodiment.
FIG. 14 is a vertical cross-sectional view of an additional intermediate structure that may be used in forming a color conversion device according to a second embodiment.
FIG. 15 is a vertical cross-sectional view of an additional intermediate structure that may be used in forming a color conversion device according to a second embodiment.
FIG. 16 is a vertical cross-sectional view of an additional intermediate structure that may be used in forming a color conversion device according to a second embodiment.
FIG. 17 is a vertical cross-sectional view of an additional intermediate structure that may be used in forming a color conversion device according to various embodiments.
FIG. 18 is a vertical cross-sectional view of an additional intermediate structure that may be used in forming a color conversion device according to various embodiments.
FIG. 19 is a vertical cross-sectional view of a light emitting device in a first configuration according to various embodiments.
FIG. 20 is an additional vertical cross-sectional view of a light emitting device in a second configuration, according to various embodiments.
FIG. 21 is an additional vertical cross-sectional view of a light emitting device in a third configuration, according to various embodiments.
FIG. 22 is a vertical cross-sectional view of a packaged light-emitting device in one configuration according to various embodiments.
FIG. 23 is a vertical cross-sectional view of a packaged light-emitting device in another configuration according to various embodiments.

A display device, such as a direct view display (e.g., an AR display), may be formed from an ordered array of pixels. Each pixel may include a set of subpixels that emit light at distinct peak wavelengths. For example, a pixel may include a red subpixel, a green subpixel, and a blue subpixel. Each subpixel may include one or more light emitting diodes that emit light of a particular wavelength. A typical arrangement has red, green, and blue (RGB) subpixels within each pixel. Each pixel may be driven by backplane circuitry, such that any combination of colors within the color gamut may be displayed on the display for each pixel. The display panel may be formed by a process in which the LED subpixels are soldered or otherwise electrically attached to bond pads located on a backplane. The bond pads may be electrically driven by the backplane circuitry and other driving electronics.

Various embodiments provide light-emitting devices configured to generate high efficiency red, green, blue, and/or other color pixelated light from shorter wavelength excitation sources using photonically pumped quantum dots. Micron-scale light-emitting diodes (micro-LEDs) having lengths and widths of less than 10 microns, such as 1 to 2 microns, may be used in AR displays and other direct view display devices. This emerging technology provides high black levels by using individual LEDs at each pixel location in the display device. Additionally, each pixel may be configured to generate light of a single color. The backplane to which the individual LEDs may be attached may include a substrate (e.g., plastic, glass, semiconductor, etc.) having thin film transistor (TFT) structures, silicon CMOS, or other driver circuitry that may be configured to independently apply voltage or current to each LED. For example, the backplane may include TFTs on a glass or plastic substrate, or bulk silicon transistors (e.g., transistors in a CMOS configuration) on a bulk silicon substrate or on a silicon-on-insulator (SOI) substrate. Although micro-LEDs are described in the embodiments below, it should be noted that other types of LEDs (e.g., nanowire or other nanostructure LEDs), or macro-LEDs having a size (e.g., width and length) greater than 10 microns may also be used instead of, or in addition to, micro-LEDs.

In some embodiments, the size of each micro-LED may be smaller than the pitch of pixels used in a particular display device, such as a direct view display device or other display device. For example, a 2000 to 8000 ppi AR display may have adjacent micro-LEDs spaced apart by less than 1 micron, such as 0.6 to 0.7 microns. It is difficult to sequentially arrange multiple different color micro-LEDs on adjacent RGB sub-pixel regions of the same pixel on the backplane with high accuracy (e.g., sequentially placing red, green, and blue emitting LEDs).

Some embodiments of the present disclosure include photon emitters based on LEDs having a low indium-doped InGaN active region (e.g., a micro-LED having a low indium content InGaN light-emitting active layer) or an undoped GaN active region (e.g., a micro-LED having a GaN light-emitting active layer) coupled with a photonically pumped color conversion material. Such LEDs may emit UV radiation or blue light having a peak emission wavelength in the ultraviolet (UV) radiation or blue light spectral range (e.g., 370 to 460 nm, for example, 390 to 420 nm, for example, 400 to 410 nm). As used herein, the blue light spectral range includes blue and violet colors as perceived by a human observer.

In one embodiment, the color conversion material may comprise quantum dots. The quantum dots may be configured to absorb photons generated by the monochromatic LEDs and generate light of various colors (e.g., red, green, and blue) depending on the properties of the quantum dots (e.g., quantum dot size and material composition).

In the size regime (e.g., less than 10 micron sizes) used in augmented reality (AR) displays (e.g., smart glasses) and other applications, the use of UV or blue emitting LEDs and photonically pumped quantum dots to generate a variety of colors may provide display devices with better uniformity across the backplane. By placing all adjacent monochrome LEDs (e.g., either UV or blue LEDs) simultaneously (e.g., from the same growth substrate) on the backplane, tighter tolerances may be more easily met than by sequentially placing adjacent red, green, and blue LEDs within adjacent subpixels of the same RGB pixel. Embodiments of the present disclosure provide methods that allow for improved alignment between the monochrome LEDs and individual quantum dots in each color subpixel by using a monochrome LED array to fabricate and align the quantum dots in the subpixels.

FIG. 1 is a vertical cross-sectional view of an intermediate structure (100) that may be used in forming a light-emitting device according to various embodiments. The intermediate structure (100) may include a plurality of LEDs (102) positioned on a substrate (104), such as a backplane. As described above, the LEDs (102) may have a peak emission wavelength in the UV radiation range or in the blue light spectral region (e.g., UV or blue emitting LEDs, also referred to as UV or blue LEDs).

In one embodiment, the LEDs (102) may have at least one first electrode (103) positioned on top of the LED and facing away from the substrate (104). The first electrode (103) may be configured as an anode or cathode electrode. In one embodiment, the LEDs (102) may be configured as vertical LEDs where the second electrode (105) is positioned between the substrate (104) and the bottom of the LED (102). For example, the second electrode (105) may be bonded to individual bonding pads on the substrate (104). In another embodiment, the LEDs (102) may include a common transparent first electrode (103) (e.g., a transparent conductive oxide electrode) positioned on their emitting side (e.g., the top side in FIG. 1 ) and separate second electrodes (105) that control whether each LED (102) is turned on or off. In other embodiments, the LEDs may be configured as lateral LEDs, where both electrodes are positioned on the same side of the LED (e.g., on the top side or bottom side of the LED).

The substrate (104) may be a backplane having electrical circuitry (e.g., TFT and/or CMOS circuits) configured to supply voltages and currents to the LEDs (102) via the second electrodes (105) to control light emission by the LEDs (102). The backplane may be an active or passive matrix backplane substrate for driving the LEDs. As used herein, "backplane substrate" refers to any substrate configured to have multiple devices attached thereto. In one embodiment, the backplane may comprise a substrate comprising silicon, glass, plastic, and/or at least another material that may provide structural support for the devices attached thereto. In one embodiment, the backplane substrate may be a passive backplane substrate having metal interconnect structures (not shown) comprising metallized lines, for example, in a cross-shaped grid, and no dedicated active devices (e.g., TFTs) for each LED. In another embodiment, the backplane substrate may be an active backplane substrate including metal interconnect structures as a cross-shaped grid of conductive lines and further including dedicated active devices (e.g., CMOS transistors or TFTs) for each LED at one or more intersections of the cross-shaped grid of conductive lines.

FIG. 2 is a vertical cross-sectional view of a light-emitting device (200) according to various embodiments. The light-emitting device (200) may include an intermediate structure (100) (see FIG. 1) including a substrate (104) and a plurality of LEDs (102, 102a, 102b, 102c) formed on the substrate (104). The second electrodes (105) are omitted from FIG. 2 for clarity. As described above, the LEDs (102) may be configured to emit blue or ultraviolet radiation incident photons (204). The light-emitting device (200) may further include a color conversion device (201). In one embodiment, the color conversion device (201) is a stand-alone device fabricated using radiation emitted by the LEDs (102) of the intermediate structure (100). That is, the color conversion device (201) is not deposited layer by layer on the intermediate structure (100), but is formed separately from the intermediate structure (100), and does not require a supporting intermediate structure (100). The completed color conversion device (201) is subsequently attached to the intermediate structure (100) using an adhesive and/or mechanical attachment to form the light emitting device (200).

The color conversion device (201) includes a color conversion material (202a, 202b, 202c) formed in a plurality of vias (302) within a matrix material (as described with respect to FIG. 3 below). As described in more detail below, the color conversion device (201) may optionally include a substrate (212) supporting the plurality of vias (302) bordered by matrix material walls (210). The substrate (212) and the walls (210) may be made of different materials or may be formed of the same material. The color conversion device (201) may further include an optional protective layer (214) that is transparent to incident photons (204). The protective layer may include aluminum oxide or another transparent material.

The light emitting device (200) may be configured as an ordered array. For example, the first color conversion material (202a) may be configured to absorb incident photons (204) and generate converted photons (206) having a first color. Similarly, the second color conversion material (202b) may be configured to absorb incident photons (204) and generate converted photons (206) having a second color, and the third color conversion material (202c) may be configured to absorb incident photons (204) and generate converted photons (206) having a third color. A certain fraction of the incident photons (204) may be reflected by the substrate (212) to become reflected photons (208). The reflected photons (208) may be recycled in the color conversion material (202a, 202b, 202c), thereby having an increased probability of being converted into photons (206) that are absorbed and converted by the color conversion material (202a, 202b, 202c). This process, sometimes referred to as “photon recycling,” may increase the quantum efficiency of the device.

In one embodiment, the light-emitting device (200) may be configured as an ordered array of pixels, each pixel including a red sub-pixel, a green sub-pixel, and a blue sub-pixel. For example, a pixel (203) may include a first (e.g., red) sub-pixel having a first LED (102a) and a corresponding first color (e.g., red) conversion material (202a), a second (e.g., green) sub-pixel having a second LED (102b) and a corresponding second color (e.g., green) conversion material (202b), and a third (e.g., blue) sub-pixel having a third LED (102c) and a third color (e.g., blue) conversion material (202c). In this manner, the color conversion materials (202a, 202b, 202c) in individual subpixels may be configured to generate red, green, and blue converted photons (206), respectively. The light emitting device (200) may be configured in various other manners in additional embodiments. For example, any number of LEDs (102) may be associated with color conversion materials that generate a single color. Accordingly, each pixel may have multiple LEDs in each subpixel. Additionally, the various subpixels may not all have the same number of pixels. In one embodiment, the LEDs (102a, 102b, 102c) may emit radiation of the same peak wavelength (e.g., UV or blue light). If the LEDs (102a, 102b, 102c) emit blue light, the third color (e.g., blue) conversion material (202c) may be omitted from the blue subpixel.

Each of the plurality of vias (302) (see FIG. 3) may be positioned over a corresponding one of the plurality of LEDs (102a, 102b, 102c) such that the color conversion material (202a, 202b, 202c) in each of the plurality of vias is configured to absorb incident photons (204) from a corresponding one of the plurality of LEDs (102) and generate converted photons (206) having a peak wavelength longer than a peak wavelength of the incident photons (204). The substrate (212) (if present) is formed of a radiation transparent material such that the converted photons (206) may be transmitted through the substrate (212).

As illustrated in FIG. 2, the color conversion device (201) may be configured as a separate (i.e., stand-alone) structure positioned over the plurality of LEDs (102). Additionally, the position of the color conversion device (201) relative to the plurality of LEDs may be adjusted such that the intensity of converted photons (206) having longer peak wavelengths is maximized, as will be described in more detail with reference to FIGS. 19-21 below. Additionally, the plurality of LEDs (102) may include micro-LEDs each having a size (i.e., length and width) of less than or equal to 10 microns, for example, from about 1 to about 2 microns. Additionally, adjacent LEDs (102) may be separated by a distance of less than or equal to 1 micron, for example, from about 0.6 micron to about 0.7 micron.

The color conversion material (202a, 202b, 202c) may include quantum dots corresponding to a variety of different colors. In this example, the color conversion material (202a, 202b, 202c) may include a plurality of first quantum dots (202a), a plurality of second quantum dots (202b), and a plurality of third quantum dots (202c) that may be configured to convert UV or blue incident photons (204) into photons having first, second, and third colors, respectively. For example, the first, second, and third colors may have different peak wavelengths in the red, green, and blue color spectral ranges. The quantum dots may have a diameter in the range of about 1 nm to about 10 nm, such as in the range of about 2 nm to 8 nm, and may be nanocrystals of a compound semiconductor material, such as a III-V semiconductor material (e.g., indium phosphide as described in U.S. Pat. No. 9,884,763 B1, which is incorporated herein by reference in its entirety), a II-VI semiconductor material (e.g., core-shell quantum dots of ZnSe, ZnS, ZnTe, CdS, CdSe, etc. as described in U.S. Patent Application Publication No. US 2017/0250322 A1, which is incorporated herein by reference in its entirety), and/or a I-III-VI semiconductor material (e.g., AgInGaS/AgGaS core-shell quantum dots as described in U.S. Pat. No. 10,927,294 B2, which is incorporated herein by reference in its entirety).

The quantum dots may emit different colored light (e.g., red, green, or blue) depending on their diameter. Larger quantum dots may emit longer wavelength light, while smaller dots may emit shorter wavelength light. The quantum dots may be suspended in a material (e.g., a polymer such as polyimide) having a refractive index that is different (e.g., higher) than the refractive index of the light extracting material (110). For example, the polyimide material may have a refractive index of 1.6 to 1.75, for example, about 1.7. If blue LEDs (102) are used, the blue emitting quantum dots may be omitted.

Each of the LEDs (102) may be configured to emit incident photons (204) having a common wavelength or within a range of target wavelengths. For example, the GaN-based LEDs (102) may emit incident photons (204) having a wavelength in the range of about 370 nm to about 430 nm, such as about 400 nm to about 410 nm (i.e., in the blue or near-UV portion of the electromagnetic spectrum). The LEDs (102) may exhibit high uniformity and may exhibit high efficiency.

FIG. 3 is a vertical cross-sectional view of an intermediate structure (300) that may be used in forming the color conversion device (201) illustrated in FIG. 2, according to various embodiments. The intermediate structure (300) may include a self-supporting support comprising a substrate (212) and a matrix material having a plurality of vias (302) formed therein. The vias (302) may be bounded by matrix material walls (210). The walls (210) and the substrate (212) may be formed of the same material. For example, the intermediate structure (300) may include a polymer material formed by an injection molding process. In other embodiments, the matrix material may include a positive-tone photosensitive polymer (210L) formed over the substrate (212) (e.g., see FIG. 17 and related description, below). The vias (302) may also be formed by selectively exposing portions of the positive-tone photosensitive polymer (210L) to blue or UV radiation that acts to create uncrosslinked polymer material portions that may be removed with a solvent (e.g., see FIG. 18 and related description below). Various other ways of forming the vias (302) within the matrix material are contemplated within the scope of the present disclosure.

In the first embodiment illustrated in FIGS. 4 to 9, quantum dot ink is selectively deposited on individual vias (302), and then irradiation is performed. In the second embodiment illustrated in FIGS. 11 to 16, quantum dot ink is non-selectively deposited on individual vias (302), and then irradiation is performed.

FIG. 4 is a vertical cross-sectional view of an additional intermediate structure (400) that may be used in forming a color conversion device (201) (e.g., see FIG. 2 ) according to a first embodiment. In this embodiment, a first quantum dot ink (402a) may be optionally introduced into a first plurality of vias (302) intended to contain first quantum dots (202a). The first quantum dot ink (402a) may include quantum dots having a first size and composition suspended in a photocurable polymer material. The first quantum dot ink (402a) may be deposited in a variety of ways. For example, the first quantum dot ink (402a) may be deposited by an inkjet printing process. The first quantum dot ink (402a) may also be exposed to blue light or UV radiation to crosslink the first photocurable polymer material, as described in more detail with reference to FIG. 5 below.

FIG. 5 is a vertical cross-sectional view of an additional intermediate structure (500) that may be used in forming a color conversion device (201) (e.g., see FIG. 2 ) according to the first embodiment. The intermediate structure (500) may include an array of LEDs positioned over the intermediate structure (400) of FIG. 4 (e.g., the intermediate structure (100) of FIG. 1 ). While the array of LEDs is shown positioned over the intermediate structure (400) to illuminate the first quantum dot ink (402a), in alternative embodiments, the array of LEDs may be positioned beneath the substrate (212) of the intermediate structure (400) to illuminate the first quantum dot ink (402a) through the substrate (212). The array of LEDs may also be used as a fabrication tool to selectively illuminate the first quantum dot ink (402a). As illustrated, the first plurality of LEDs (102a) may be selectively turned on to expose the first quantum dot ink (402a) to blue light or UV radiation (502). In this manner, the blue light or UV radiation (502) may cause the first quantum dot ink (402a) to crosslink to form the first color conversion material (202a). Accordingly, the first LEDs (102a) (e.g., LEDs positioned in red subpixels in the final device (201)) may be used to expose the first quantum dot ink (402a) to form the first (e.g., red) color conversion material (202a) in the red subpixels.

FIG. 6 is a vertical cross-sectional view of an additional intermediate structure (600) that may be used in forming a color conversion device (201) (e.g., see FIG. 2 ) according to the first embodiment. A second quantum dot ink (402b) may be introduced into the second plurality of vias (302), as illustrated. The second quantum dot ink (402b) may include quantum dots having a second size and/or composition that is different from the first size and/or composition suspended in the photocurable polymer material. The second quantum dot ink (402b) may be exposed to blue light or UV radiation to crosslink the second photocurable polymer material, as described in more detail with reference to FIG. 7 below.

FIG. 7 is a vertical cross-sectional view of an additional intermediate structure (700) that may be used in forming a color conversion device (201) (e.g., see FIG. 2 ) according to the first embodiment. The intermediate structure (700) may include an array of LEDs (e.g., the intermediate structure (100) of FIG. 1 ) positioned above or below the intermediate structure (600) of FIG. 6 . As illustrated, a second plurality of LEDs (102b) may be selectively turned on to expose the second quantum dot ink (402b) to blue light or UV radiation (502). In this manner, the blue light or UV radiation (502) may cause the second quantum dot ink (402b) to crosslink to form the second color conversion material (202b). Thus, the second LEDs (102b) (e.g., LEDs positioned in green subpixels in the final device (201)) may be used to expose the second quantum dot ink (402b) to form a second (e.g., green) color conversion material (202b) in the green subpixels.

FIG. 8 is a vertical cross-sectional view of an additional intermediate structure (800) that may be used in forming a color conversion device (201) (e.g., see FIG. 2 ) according to the first embodiment. If a third color conversion material (202c) is present in the final device (201), a third quantum dot ink (402c) may be introduced into the third plurality of vias (302) (e.g., see FIG. 3 ), as illustrated. The third quantum dot ink (402c) may include quantum dots having a third size and composition that is different from the first and second sizes and/or compositions suspended in the photocurable polymer material. The third quantum dot ink (402c) may be exposed to blue light or UV radiation to crosslink the third photocurable polymer material, as described in more detail with reference to FIG. 9 , below.

FIG. 9 is a vertical cross-sectional view of an additional intermediate structure (900) that may be used in forming a color conversion device (201) (e.g., see FIG. 2 ) according to the first embodiment. The intermediate structure (900) may include an array of LEDs (e.g., the intermediate structure (100) of FIG. 1 ) positioned above or below the intermediate structure (800) of FIG. 8 . As illustrated, a third plurality of LEDs (102c) may be selectively turned on to expose the third quantum dot ink (402c) to blue light or UV radiation (502). In this manner, the blue light or UV radiation (502) may cause the third quantum dot ink (402c) to crosslink to form the third color conversion material (202c). Accordingly, the third LEDs (102c) (e.g., LEDs positioned in blue subpixels in the final device (201)) may be used to expose the third quantum dot ink (402c) to form a third (e.g., blue) color conversion material (202c) in the blue subpixels. Alternatively, if the LEDs (102) include blue LEDs, the steps of FIGS. 8 and 9 may be omitted.

FIG. 10 is a vertical cross-sectional view of a color conversion device (201) (e.g., see FIG. 2 ) according to various embodiments. As illustrated, the color conversion device (201) may further include a protective layer (214) formed over the color conversion materials (202a, 202b, 202c). In one embodiment, the protective layer (214) may be a thin layer of Al ₂ O ₃ , which may be deposited using an atomic layer deposition (ALD) process. The protective layer (214) may have a thickness in the range of about 5 nm to about 50 nm. Alternatively, the protective layer (214) may be formed of various other materials using other deposition processes and may have other thicknesses. The protective layer (214) may be configured to protect the color conversion material (202a, 202b, 202c) while allowing incident photons (204) to transmit through the protective layer (214) (e.g., see FIG. 2).

FIG. 11 is a vertical cross-sectional view of an additional intermediate structure (1100) that may be used in forming a color conversion device (201) (e.g., see FIG. 2 ) according to a second embodiment. In this embodiment, a spin-coating process may be used to non-selectively deposit a first quantum dot ink (402a) on all of the vias (302) within the intermediate structure (300) of FIG. 3. As described above, the first quantum dot ink (402a) may include quantum dots having a first size and composition suspended in a photocurable polymer material. The first quantum dot ink (402a) may be exposed to blue light or UV radiation to crosslink the first photocurable polymer material, as described in more detail with reference to FIG. 12 below.

FIG. 12 is a vertical cross-sectional view of an additional intermediate structure (1200) that may be used in forming a color conversion device (201) (e.g., see FIG. 2 ) according to a second embodiment. The intermediate structure (1200) may include an array of LEDs (e.g., the intermediate structure (100) of FIG. 1 ) positioned above or below the intermediate structure (1100) of FIG. 11 . The array of LEDs may be used as a manufacturing tool to selectively illuminate the first quantum dot ink (402a). As illustrated, the first plurality of LEDs (102a) may be selectively turned on to expose the first (e.g., red) quantum dot ink (402a) to blue light or UV radiation (502). In this manner, the blue light or UV radiation (502) may cause the first quantum dot ink (402a) in some of the vias (302) (e.g., in the vias located in the red subpixels) to crosslink (i.e., cause the photocurable polymer material of the ink to crosslink) to form the first color conversion material (202a).

FIG. 13 is a vertical cross-sectional view of an additional intermediate structure (1300) that may be used in forming a color conversion device (201) (e.g., see FIG. 2 ) according to a second embodiment. In this regard, portions of the first quantum dot ink (402a) that were not illuminated in the intermediate structure (1200) (e.g., see FIG. 12 ) (e.g., red quantum dot ink positioned in the green and blue sub-pixel vias (302)) may be selectively removed because the photocurable polymer material of the ink in these vias (302) was not crosslinked by the illumination.

Next, a spin-coating process may be used to deposit a second (e.g., green) quantum dot ink (402b) into the plurality of vias (302) that were not illuminated in the intermediate structure (1200) of FIG. 12 (i.e., vias that are not already filled with the first color conversion material (202a)). As described above, the second quantum dot ink (402b) may include quantum dots having a second size and composition that is different from the first size and/or composition suspended in the photocurable polymer material. The second quantum dot ink (402b) may be exposed to blue light or UV radiation to crosslink the second photocurable polymer material, as described in more detail with reference to FIG. 14 below.

FIG. 14 is a vertical cross-sectional view of an additional intermediate structure (1400) that may be used in forming a color conversion device (201) (e.g., see FIG. 2 ) according to a second embodiment. The intermediate structure (1400) may include an array of LEDs (e.g., the intermediate structure (100) of FIG. 1 ) positioned above or below the intermediate structure (1300) of FIG. 13 . The array of LEDs may be used as a manufacturing tool to selectively illuminate the second quantum dot ink (402b). As illustrated, the second plurality of LEDs (102b) may be selectively turned on to expose the second quantum dot ink (402b) to blue light or UV radiation (502). In this manner, the blue light or UV radiation (502) may cause the second quantum dot ink (402b) to cross-link to form a second color conversion material (202b) in the individual vias (302) (e.g., in the vias (302) located in the green sub-pixels).

FIG. 15 is a vertical cross-sectional view of an additional intermediate structure (1500) that may be used in forming a color conversion device (201) (e.g., see FIG. 2) according to a second embodiment. Portions of the second quantum dot ink (402b) that were not illuminated (and not cross-linked) in the intermediate structure (1400) (e.g., see FIG. 14) may be selectively removed.

If a third color conversion material (202c) is included in the final device (201) (e.g., if the LEDs (102) are UV LEDs), a spin-coating process may be used to deposit a third quantum dot ink (402c) into a plurality of vias (302) that were not illuminated in the intermediate structure (1400) of FIG. 14 (i.e., vias (302) that are not already filled by the first and second color conversion materials (202a and 202b)). As described above, the third quantum dot ink (402c) may include quantum dots having a third size and composition that is different from the first and second sizes and/or compositions suspended in the photocurable polymer material. The third quantum dot ink (402c) may also be exposed to blue light or UV radiation to crosslink the second photocurable polymer material, as described in more detail with reference to FIG. 16 below.

FIG. 16 is a vertical cross-sectional view of an additional intermediate structure (1600) that may be used in forming a color conversion device (201) (e.g., see FIG. 2 ) according to a second embodiment. The intermediate structure (1600) may include an array of LEDs (e.g., the intermediate structure (100) of FIG. 1 ) positioned over the intermediate structure (1500) of FIG. 15 . The array of LEDs may be used as a manufacturing tool to selectively illuminate the third quantum dot ink (402c). As illustrated, the third plurality of LEDs (102c) may be selectively turned on to expose the third quantum dot ink (402c) to blue light or UV radiation (502). In this manner, the blue light or UV radiation (502) may cause the third quantum dot ink (402c) to crosslink to form a third color conversion material (202c) (e.g., in the vias (302) located in the blue subpixels).

As mentioned above, the intermediate structure (300) of FIG. 3 may be formed in various ways in individual embodiments. For example, the substrate (212) and the matrix material having the vias (302) formed therein may be formed by an injection molding process using a polymer material. In other embodiments described below, the substrate and matrix material may be different materials.

FIG. 17 is a vertical cross-sectional view of an additional intermediate structure (1700) that may be used in forming a color conversion device (201) (e.g., see FIG. 2 ), according to various embodiments. As illustrated in FIG. 17 , the matrix material may include a positive-tone photosensitive polymer (i.e., matrix material) (210L) formed on a substrate (212). The substrate (212) may be a transparent polymer material having sufficient mechanical strength to support the positive-tone photosensitive polymer (210L) formed thereon.

FIG. 18 is a vertical cross-sectional view of an additional intermediate structure (1800) that may be used in forming a color conversion device (201) (e.g., see FIG. 2 ), according to various embodiments. In this regard, the intermediate structure (1800) may include an array of LEDs (e.g., the intermediate structure (100) of FIG. 1 ) positioned above or below the intermediate structure (1700) of FIG. 17 . The array of LEDs may be used as a manufacturing tool to selectively illuminate exposed portions (210X) of the positive-tone photosensitive polymer (210L).

As illustrated, all of the LEDs (102) may be tuned to expose the exposed portions (210X) to blue light or UV radiation (502). In this manner, the blue light or UV radiation (502) may cause the exposed portions (210X) of the positive-tone photosensitive polymer (210L) to crosslink. The exposed portions (210X) may then be removed by dissolution in a solvent. After removal of the exposed portions (210X), a plurality of unexposed portions (210U) may remain. In this manner, the unexposed portions (210U) of the matrix material become the matrix material walls (210) of the intermediate structure (300) of FIG. 3.

FIGS. 19-21 illustrate a method of alignment between an LED array (e.g., the intermediate structure (100) of FIG. 1) and a self-contained color conversion device (201). According to various embodiments, FIG. 19 is a vertical cross-sectional view of a light emitting device (200) in a first configuration, FIG. 20 is a further vertical cross-sectional view of the light emitting device (200) in a second configuration, and FIG. 21 is a further vertical cross-sectional view of the light emitting device (200) in a third configuration. The light emitting device (200) may include an array of LEDs (e.g., the intermediate structure (100) of FIG. 1) positioned above or below a color conversion device (201) including a color conversion material (202a, 202b, 202c).

As illustrated in FIG. 19, the first plurality of LEDs (102a) may be turned on to generate first incident photons (204a) that may be absorbed by the first color conversion material (202a) to generate first converted photons (206a) having a first color (e.g., red color). The first converted photons (206a) may be detected by a photodetector (e.g., a spectrometer) (220) configured to measure the intensity of the first converted photons (206a).

In one embodiment, a method of positioning a color conversion device (201) relative to an array of LEDs (e.g., an intermediate structure (100) of FIG. 1) comprises adjusting a position of the color conversion device (201) relative to the LEDs (102a) to maximize an intensity of first converted photons (206a). The method may include determining a first maximum intensity of the first converted photons (206a) as a first function of a position of the color conversion device (201) relative to the first plurality of LEDs (102a) along a first direction (e.g., the x-direction) (1602) in a two-dimensional plane (e.g., the x-z plane) parallel to an interface between the color conversion device (201) and a substrate (104) (e.g., parallel to a surface of a passivation layer (114)). The method may further include determining a second maximum intensity of the first converted photons (206a) as a second function of a position of the color conversion device (201) relative to the first plurality of LEDs (102a) along a second direction (e.g., the z-direction into the plane of FIG. 19) in a two-dimensional plane (e.g., the x-z plane) parallel to an interface between the color conversion device (201) and the substrate (104).

As illustrated in FIG. 20, the second plurality of LEDs (102b) may be turned on to generate second incident photons (204b) that may be absorbed by the second color conversion material (202b) to generate second converted photons (206b) having a second color. The second converted photons (206b) may be detected by a photodetector (220) configured to measure the intensity of the second converted photons (206b).

In one embodiment, a method of positioning a color conversion device (201) relative to an array of LEDs may further include adjusting a position of the color conversion device (201) relative to the LEDs (102b) to maximize an intensity of the second converted photons (206b). The method may include determining a third maximum intensity of the second converted photons (206b) as a third function of a position of the color conversion device (201) relative to the second plurality of LEDs (102b) along a first direction (1602) in a two-dimensional plane parallel to an interface between the color conversion device (201) and the substrate (104) (e.g., parallel to a surface of the protective layer (114)). The method may further include determining a fourth maximum intensity of the second converted photons (206b) as a second function of a position of the color conversion device (201) relative to the second plurality of LEDs (102b) along a second direction (e.g., into the plane of FIG. 20 ) in a two-dimensional plane parallel to an interface between the color conversion device (201) and the substrate (104).

As illustrated in FIG. 21, the third plurality of LEDs (102c) may be turned on to generate third incident photons (204c) that may be absorbed by the third color conversion material (202c) to generate third converted photons (206c) having a third color. The third converted photons (206c) may be detected by a detector configured to measure the intensity of the third converted photons (206c).

In one embodiment, a method of positioning a color conversion device (201) with respect to an array of LEDs may further include adjusting a position of the color conversion device (201) with respect to the LEDs (102c) to maximize an intensity of the third converted photons (206c). The method may include determining a fifth maximum intensity of the third converted photons (206c) as a third function of a position of the color conversion device (201) with respect to the third plurality of LEDs (102c) along a first direction (1602) in a two-dimensional plane parallel to an interface between the color conversion device (201) and the substrate (104) (e.g., parallel to a surface of the protective layer (114)). The method may further include determining a sixth maximum intensity of the third converted photons (206c) as a second function of a position of the color conversion device (201) relative to the third plurality of LEDs (102c) along a second direction (e.g., into the plane of FIG. 21) in a two-dimensional plane parallel to an interface between the color conversion device (201) and the substrate (104).

The method described above determines a first position, a second position, a third position, a fourth position, a fifth position, and a sixth position corresponding to a first maximum intensity, a second maximum intensity, a third maximum intensity, a fourth maximum intensity, a fifth maximum intensity, and a sixth maximum intensity, respectively. The first position, the second position, the third position, the fourth position, the fifth position, and the sixth position may then be averaged to determine an optimal position of the color conversion device (201) with respect to the array of LEDs.

Alternatively, a first position may be determined that maximizes the intensity of a first color, a second position may be determined that maximizes the intensity of a second color, and a third position may be determined that maximizes the intensity of a third color. Each of the first position, the second position, and the third position may represent a relative two-dimensional position of the color conversion device (201) with respect to the plurality of LEDs. Then, by averaging the first position, the second position, and the third position, an optimal position of the color conversion device (201) may be determined. Thus, two positions along two perpendicular directions in the plane determined for each color may serve as two-dimensional coordinates for a single point that maximizes the intensity of each color.

In additional embodiments, the method may also include adjusting an orientation angle (not shown) of the color conversion device (201) relative to the array of LEDs. For example, for a fixed position in a two-dimensional plane, the color conversion device (201) may be tilted relative to a plane (e.g., an x-y plane) parallel to an interface between the color conversion device (201) and the substrate (104). A first orientation angle may be determined that maximizes the intensity of a first color of converted photons, a second orientation angle may be determined that maximizes the intensity of a second color of converted photons, and a third orientation angle may be determined that maximizes the intensity of a third color of converted photons. An optimal orientation of the color conversion device (201) relative to the array of LEDs may then be determined based on the first orientation angle, the second orientation angle, and the third orientation angle.

After the self-contained color conversion device (201) is aligned with respect to the array of LEDs (102) in an optimal position, the color conversion device (201) is attached to the array of LEDs (102) using adhesive and/or mechanical attachment features (e.g., clamps, brackets, housing, etc.). Thus, the self-contained color conversion device (201) allows for improved alignment with respect to the LEDs (102) than if layers of the color conversion device were deposited one by one over the LEDs, which would avoid a post manufacture alignment step.

FIG. 22 is a vertical cross-sectional view of a packaged light-emitting device (2200) in one configuration, according to various embodiments. An optically transparent insulating filler (216), such as silicon oxide or a polymer, may be formed between the LEDs (102). The light-emitting device (2200) includes a housing (e.g., package) (218) that is transparent to visible light or has a window thereon that is transparent to visible light. The package (218) may include a polymeric material. The package (218) holds the self-contained color conversion device (201) and the LED array (100) together after the optical alignment steps described above.

In one embodiment, the alignment protrusions (220) may be used to align the self-contained color conversion device (201) and the LED array (100). The protrusions (220) may be positioned on the upper surface of the LED array (100) and inserted into individual grooves in the lower surface of the self-contained color conversion device (201) to form an interlocking pattern. Alternatively, the protrusions (220) may be positioned on the upper surface of the self-contained color conversion device (201) and inserted into individual grooves in the lower surface of the LED array (100). Alternatively, the protrusions are positioned on both surfaces and inserted into opposing grooves on opposing surfaces. The protrusions (220) may comprise any material, such as an insulating material, a semiconductor material, or a conductive material. For example, the protrusions may comprise protruding portions of the insulating filler (216) and/or the protective layer (214). The grooves may be formed in the protective layer (214) and/or in the insulating filler (216).

In an alternative embodiment of the packaged device (2300) illustrated in FIG. 23, instead of using dedicated alignment protrusions (220) and corresponding grooves, the LEDs (102) themselves may be used as alignment features by fitting into the grooves in the stand-alone color conversion device (201). The grooves may be located in the passivation layer (214) and/or in the color conversion material (202). For example, the color conversion material (202) may be underfilled into the vias (302), leaving the grooves above the color conversion material (202) between the matrix material walls (210). The passivation layer (214) may partially fill the grooves, leaving the remainder of the grooves to be filled with the LEDs (102). Thus, the grooves in this embodiment include the unfilled portions of the vias (302) described above.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the disclosed embodiments. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the following claims and the principles and novel features disclosed herein.

Claims (20)

A method for forming a light-emitting device, comprising:
A step of providing a self-supporting support comprising a matrix material containing first and second vias;
A step of depositing a first photocurable quantum dot ink comprising a first plurality of quantum dots suspended in a first photocurable polymer material into the first vias within the matrix material;
A step of illuminating the first photocurable quantum dot ink with ultraviolet radiation or blue light from first light-emitting diodes of the array of light-emitting diodes to crosslink the first photocurable polymer material in the first vias;
A step of depositing a second photocurable quantum dot ink comprising a second plurality of quantum dots suspended in a second photocurable polymer material, wherein the second plurality of quantum dots are configured to emit light having a different peak wavelength than the first plurality of quantum dots, into the second vias in the matrix material;
illuminating the second photocurable quantum dot ink with ultraviolet radiation or blue light from second light emitting diodes of the array of light emitting diodes to crosslink the second photocurable polymer material in the second vias; and
A method of forming a light-emitting device, comprising the step of attaching the free-standing support to the array of light-emitting diodes after the steps of illuminating the first and second photocurable quantum dot inks. In the first paragraph,
A method of forming a light emitting device, wherein the matrix material further comprises third vias. In the second paragraph,
A step of depositing a third photocurable quantum dot ink comprising a third plurality of quantum dots suspended in a third photocurable polymer material into the third vias in the matrix material, wherein the third plurality of quantum dots are configured to emit light having a different peak wavelength than the first and second pluralities of quantum dots; and
A method of forming a light-emitting device, further comprising the step of illuminating the third photocurable quantum dot ink with ultraviolet radiation or blue light from third light-emitting diodes of the array of light-emitting diodes to crosslink the third photocurable polymer material in the third vias prior to the attaching step. In the third paragraph,
A method of forming a light emitting device, further comprising the step of forming the first vias, the second vias, and the third vias in a single via formation operation. In paragraph 4,
A method for forming a light emitting device, wherein the matrix material including the first vias, the second vias, and the third vias is formed by injection molding, and the matrix material includes a polymer material. In the third paragraph,
A method for forming a light-emitting device, wherein the matrix material comprises a positive-tone photosensitive polymer formed on a first substrate. In Article 6,
selectively illuminating the first, second and third portions of the positive-tone photosensitive polymer with individual first, second and third light-emitting diodes of the array of light-emitting diodes to form non-crosslinked polymer material in the first, second and third portions of the matrix material, respectively; and
A method for forming a light emitting device, further comprising the step of forming the first vias, the second vias, and the third vias by removing the non-crosslinked polymer material from the first portions, the second portions, and the third portions, respectively. In the third paragraph,
The step of depositing the first photocurable quantum dot ink into the first vias within the matrix material comprises the step of selectively depositing the first photocurable quantum dot ink only into the first vias;
The step of depositing the second photocurable quantum dot ink into the second vias within the matrix material comprises the step of selectively depositing the second photocurable quantum dot ink only into the second vias after the step of illuminating the first photocurable quantum dot ink; and
A method of forming a light-emitting device, wherein the step of depositing the third photocurable quantum dot ink into the third vias within the matrix material comprises the step of selectively depositing the third photocurable quantum dot ink only into the third vias after the step of illuminating the second photocurable quantum dot ink. In the third paragraph,
The step of depositing the first photocurable quantum dot ink into the first vias within the matrix material comprises the step of non-selectively depositing the first photocurable quantum dot ink into the first, second and third vias, and then removing uncrosslinked portions of the first photocurable quantum dot ink from the second and third vias after the step of illuminating the first photocurable quantum dot ink;
The step of depositing the second photocurable quantum dot ink into the second vias within the matrix material comprises the step of non-selectively depositing the second photocurable quantum dot ink into the second and third vias, and then removing uncrosslinked portions of the second photocurable quantum dot ink from the third vias after the step of illuminating the second photocurable quantum dot ink; and
A method of forming a light-emitting device, wherein the step of depositing the third photocurable quantum dot ink into the third vias within the matrix material comprises the step of depositing the third photocurable quantum dot ink into the third vias after the step of illuminating the third photocurable quantum dot ink. In the first paragraph,
A method for forming a light-emitting device, further comprising the step of forming a protective layer over a color conversion device. In the first paragraph,
A method for forming a light-emitting device, wherein the self-supporting support containing the first and second quantum dots comprises a color conversion device. In Article 11,
A step of forming protrusions on a matching surface of at least one of the color conversion device and the array of light-emitting diodes;
forming recesses in the matching surface of at least one of the color conversion device and the array of light-emitting diodes; and
A method of forming a light emitting device, further comprising the step of attaching the color conversion device to the array of light emitting diodes such that the protrusions are inserted into individual grooves to form an interlocking pattern to align the color conversion device and the array of light emitting diodes. In Article 11,
The first and second vias are partially filled with the cross-linked first and second photocurable polymer materials, leaving grooves;
A method of forming a light emitting device, wherein the array of light emitting diodes (LEDs) includes protrusions inserted into individual grooves to form an interlocking pattern to align the color conversion device and the array of light emitting diodes. A method for forming a light-emitting device, comprising:
A step of providing a plurality of light emitting diodes on a substrate such that the plurality of light emitting diodes are configured to emit blue light or ultraviolet radiation incident photons;
A step of providing a color conversion device including a color conversion material formed in a plurality of vias within a matrix material;
A step of positioning the color conversion device relative to the plurality of light-emitting diodes such that each of the plurality of vias is positioned over a corresponding light-emitting diode among the plurality of light-emitting diodes, wherein the color conversion material in each of the plurality of vias is configured to absorb the incident photons from the corresponding light-emitting diode among the plurality of light-emitting diodes and generate converted photons having a peak wavelength longer than a peak wavelength of the incident photons; and
A method of forming a light emitting device, comprising the step of adjusting the position of the color conversion device with respect to the plurality of light emitting diodes to maximize the intensity of the converted photons having the longer peak wavelength. In Article 14,
The step of adjusting the position of the color conversion device for the plurality of light-emitting diodes is:
A step of determining a first maximum intensity of converted photons as a first function of a position of the color conversion device with respect to the plurality of light-emitting diodes along a first direction in a two-dimensional plane parallel to an interface between the color conversion device and the substrate;
determining a second maximum intensity of converted photons as a second function of a position of the color conversion device with respect to the plurality of light-emitting diodes along a second direction in the two-dimensional plane parallel to the interface between the color conversion device and the substrate; and
A method of forming a light emitting device, further comprising the step of determining a maximum intensity of converted photons as a function of an orientation angle of the color conversion device for the plurality of light emitting diodes in a two-dimensional plane parallel to an interface between the color conversion device and the substrate. As a light-emitting device,
substrate;
a plurality of light emitting diodes positioned on the substrate and configured to emit blue or ultraviolet radiation incident photons; and
A color conversion device comprising a color conversion material positioned in a plurality of vias within a matrix material,
Each of said plurality of vias is positioned over a corresponding light emitting diode among said plurality of light emitting diodes such that the color conversion material in each of said plurality of vias absorbs the incident photons from the corresponding light emitting diode among said plurality of light emitting diodes and generates converted photons having a peak wavelength longer than a peak wavelength of the incident photons, and
A light-emitting device, wherein the color conversion device is a self-supporting structure attached on top of the plurality of light-emitting diodes. In Article 16,
Each of said plurality of light emitting diodes comprises a width of less than 10 microns, and adjacent light emitting diodes are separated by a distance of less than 1 micron;
The above color conversion material comprises quantum dots;
The quantum dots are configured to absorb the incident photons and emit the converted photons having a color of one of red, green, or blue; and
A light emitting device wherein the plurality of vias within the matrix material are arranged in an ordered array of pixels, each pixel including a red sub-pixel, a green sub-pixel, and a blue sub-pixel, wherein the color conversion material in the individual sub-pixels is configured to generate red, green, and blue converted photons, respectively. In Article 16,
At least one of the color conversion device and the plurality of light-emitting diodes contains protrusions on the matching surface;
At least one of the color conversion device and the plurality of light emitting diodes contains grooves in the matching surface; and
A light emitting device wherein the protrusions are inserted into individual grooves to form an interlocking pattern for aligning the color conversion device and the plurality of light emitting diodes. In Article 16,
The above plurality of vias are partially filled with the color conversion material, leaving grooves; and
A light emitting device, wherein the plurality of light emitting diodes (LEDs) include protrusions inserted into individual grooves to form an interlocking pattern to align the color conversion device and the plurality of light emitting diodes. In Article 16,
A light emitting device, wherein the color conversion device and the plurality of light emitting diodes are held together by at least one of an adhesive or mechanical attachment feature.